Wax emulsions containing proteinaceous emulsifiers

ABSTRACT

Aqueous wax emulsions are provided comprising a proteinaceous emulsifier, a clay and a urea-formaldehyde resin. Also provided are articles of manufacture comprising cellulosic materials containing the aforementioned wax emulsion as a coating or waterproofing agent.

States Patent 1 1 1111 3,869,414

Campbell Mar. 4, 1975 1 WAX EMULSIONS CONTAINING 2.104.077 1/1938 Groskopf 252/3115 PROTEINACEOUS EMULSIFIERS 2.567.433 9/1951 Heijmer 260/29.4 2,620,316 12/1952 12115011 260/6 {75] lnventor: Craig C. Campbell, Cherry Hill, NJ.

173] Assignee: Mobil Oil Corporation, New York.

122] Filed: Dec. 22, 1969 1211 Appl. No: 887,413

152] US. Cl 260/6, 260/28, 260/29.3, 106/272, 106/271, 252/3115 151 Int. Cl B0lj 13/00 [58] Field of Search 252/311, 356, 8.6, 311.5; 106/270, 271, 272; 260/285, 6, 29.6, 29.3

[56] References Cited UNITED STATES PATENTS 1.549.436 3/1925 Billinghame 252/3115 OTHER PUBLICATIONS Bennett Practical Emulsions, Chemical Publishing Co., lnc., Brooklyn, N.Y., (1943), p. 443.

Primary Examiner.lohn D. Welsh Attorney, Agent, or FirmCharles A. Huggett; Benjamin 1. Kaufman; Raymond W. Barclay [57] ABSTRACT Aqueous wax emulsions are provided comprising a proteinaceous emulsifier, a clay and a ureaformaldehyde resin. Also provided are articles of manufacture comprising cellulosic materials containing the aforementioned wax emulsion as a coating or waterproofing agent.

5 Claims, No Drawings WAX EMULSIONS CONTAINING PROTEINACEOUS EMULSIFIERS BACKGROUND OF THE INVENTION I. Field of the Invention This invention relates to wax emulsions and, in one of its aspects, relates more particularly to wax emulsions having specific utility as coating or waterproofing agents, for example, in the manufacture of articles comprised of cellulosic materials, such as particle board or other materials of construction, as well as having utility for such purpose in a wide variety of industrial applications.

ll. Description of the Prior Art Wax emulsions intended for use in such applications as, for example, coating materials for various types of surfaces. particle board manufacture or as waterproofing agents embodied in various types of materials, necessitate a combination of properties which include satisfactory shear stability, pumpability, noncorrosiveness and compatibility with various types of commercially employed resinous materials in a wide variety of applications. Furthermore, the ability to produce wax emulsions possessing the aforementioned properties and, at the same time, having a relatively high wax-solids content, is especially desirable from a standpoint of present-day industrial requirements. Although emulsions have heretofore been produced which may possess some of the aforementioned characteristics, nevertheless, prior to the present invention, no satisfactory wax emulsion has been obtained in which all of the aforementioned desired properties are present.

SUMMARY OF THE INVENTION In accordance with the present invention, and in accordance with its objects, there are provided new and improved wax emulsions which possess good stability under shearing stress, a relatively high degree of pumpability, non-corrosiveness to mechanical apparatus and compatibility with industrial-type resins, and furthermore, possessing the ability to have incorporated therein a relatively high wax-solids content, namely as high as at least about 50 per cent, by weight, of the total wax emulsion.

In its generic aspects, as more fully hereinafter described, the novel wax emulsions of the present invention comprise, in addition to wax, a proteinaceous emulsifier, a clay, a ureaformaldehyde resin and water. With respect to the individual components employed for producing the novel wax emulsions of the present invention, the wax component is employed in an amount from about 25 to about 70, and preferably from about 45 to about 65 per cent, by weight, of the total quantity of the emulsion. The proteinaceous emulsifier is employed in an amount from about 0.2 to about 10. and preferably from about 0.5 to about 3 per cent, by weight, of the total quantity of the emulsion. The clay component is employed in an amount from about 0.5 to about 10, and preferably from about I to about 5 per cent by weight of the total quantity of the emulsion. The urea-formaldehyde resin is employed in an amount from about 0.5 to about 15, and preferably from about I to about 5 per cent, by weight, of the total quantity of the emulsion. Sufficient water is employed to balance the formulation.

The waxes employed in preparing the novel emulsion of the present invention are preferably paraffin waxes and may be obtained from various sources such as, for example, from petroleum distillation processes, or may comprise petroleum waxes derived from distillate fractions of crude oils by such processes as solvent dewaxing, chilling, sweating, pressing or deoiling. The paraffin wax may be employed in a form in which normal paraffins predominate, although waxes entirely devoid of normal paraffins may also be employed. In a preferred form, the paraffin waxes employed may possess melting points within the range from about F. to about 200 F. In this respect, paraffin waxes having melting points between about F. and about F. are most desirable, thereby avoiding the formation of emulsions which may possibly cause staining when applied to certain cellulosic surfaces. It should also be noted that the waxes employed in the emulsions of the present invention may include paraffin waxes in combination with microcrystalline waxes, as well as slack wax.

The proteinaceous emulsifier in the novel emulsions of the present invention may be animal or vegetable and may comprise any emulsifier which is amphoteric in nature in order to overcome resin incompatibility normally encountered in other resin-containing wax emulsions. Exemplary of these emulsifiers are protein comprising, or obtained from, soybean, soybean flour, alpha-soy protein, soluble blood, blood albumen, casein, egg albumen, enzymes, gelatin and may also include, if so desired, solubilizers for the protein.

The presence of the clay component is of significant importance with respect to its use in a high solids content wax emulsion. In this respect, as hereinafter discussed, it has been found that the clay imparts shelf stability to the high solids wax emulsions of the present invention. Thus, it has been found that protein wax emulsions having a solids content below 40%, and without containing clay, exhibited good shelf stability. However, protein wax emulsions having a solids content above 40% were found to be unstable and exhibited the presence of a thick cream layer after about 48 hours. In this regard it was found that the presence of the clay eliminated undesirable creaming and imparted good shelf stability. In theory it is believed that upon homogenization the wax and the protein form a protective colloid around each individual clay particle, thus providing improved emulsion stability. Thus it has been found that the clay particles combine with the wax to form a more dense wax-clay-protein complex. The increased density of these particles results in a reduction of particle velocity thus aiding stabilization in terms of Stokes Law. The clays suitable for such use of the present emulsion may be of any nature, and preferably comprise natural clays. Exemplary thereof are industrial Kaolin clays as used for paper coating. Any clay comprising hydrated aluminum silicate (Al O -2SiO QI-I O) may also be used. Finely divided quartz, feldspar, or mica may also be present along with iron, titanium, calcium, magnesium, potassium, sodium, manganese, copper, sulfur and carbon.

The ureaformaldehyde resin employed in the wax emulsion of the present invention improve the shear stability of the wet system, and after decomposition under heat, furnish free formaldehyde to polymerize the protein. As a result, the protein loses all of its surfactant properties and re-wetting can not occur. The

application of wax is thus rendered highly efficient, inasmuch as the clay-resin-wax complex remains on the surface of the cellulosic particles. Penetration of wax into these particles is minimized since the complex is Final blending was carried out for a period of minutes.

ln Examples 5 through of Table 1. 2,000 gram batches were prepared employing a two-stage Mantonfixed by means of protein-urea-formaldehyde poly- 5 Gaulin homogenizer. The emulsions of Examples 5 merization on the cellulosic particle surface. In this through 10. as exemplified by Example 6, were premanner water resistance is improved. The ureapared in the following order; formaldehyde resin may be employed in any form and S 1 in general may comprise any ofthe commercially avail- A 30 per cent mixture of the proteinaceous material able resins of this type. Exemplary thereof are urea- 10 was prepared by employing 70 grams of water. with formaldehyde resins having a viscosity of 800-].200 slow stirring. and then adding 30 grams of powdered cps. at 65% solids. Although urea-formaldehyde resins proteinaceous material. This mixture was maintained at used for d nd ng are preferred. any ur llroom temperature (75 F. The water phase was next formaldehyde resin may be suitable based upon characprepared for use at an ultimate temperature at 175 F. teriStiCS Of urea/formaldehyde rati gr of P P by employing 677.2 grams of water and heating to a lymerization, and included catalyst (if any). Urea crystemperature of 140 F. The wax phase was then pretals and/or thiourea may also be present and are within pared for use at a temperature at 140 F. by employing the scope of the present emulsion. 1.157 grams of wax (with oil. if required) and then In as far as the cellulosic materials, coated with the heating to 140 F. 12.0 grams of ammonia, 41.8 grams novel wax emulsions of the present invention. are conof natural clay and 12 grams of the sodium salt of pencerned. it should be noted that these materials may intachlorophenol were weighed out. clude wood. paper, pressboard, cotton cloth, cotton Step II tape. gypsum board (cellulosic facings). corrugated The aforementioned quantity of water, maintained at board. bagasse. jute, and flax fiber. 140 F.. was placed into a suitable container and the The novel wax emulsions of the presentinvention are protein mixture and ammonia were added with slow applied to the desired surface in any manner which is stirring. The aforementioned wax phase was added IO ri i S h li i may b effect d b br hthe water phase with continued stirring at a temperaing. dipping, by employing any conventional spray ture of 140 F. Finally. clay and the sodium salt of penequipment or other conventionally known means of aptachlorophenol were added with continued stirring. plication for wax emulsions in general. 31) Step ill The above-described formulation was then subjected DESCRIPTION OF SPECIFIC EMBODIMENTS to homogenization in a two-stage Manton- Gaulin homogenizer for the equivalent of two passes at 140 F. The following examples. and comparative data will l yi 2 500/5()() pgi on h two valves, Th f serve to illustrate the novel wax emulsions ofthe pres- 3 l ii n was then cooled to a temperature of about ent invention. their method or preparation and their 100 to 110F, by heat exchange. The container was comparative superiority over other wax emulsions emmaintained in this condition for 16 hours until cooled ployed for similar purposes. to room temperature.

The emulsions of Examples 1 through 4 in the follow- Step lV ing Table l. were prepared in 200 gram batches em- To the above-described homogenized basic formulaploying a blender. These emulsions were prepared in tion were added 3 per cent urea-formaldehyde resin, by the following order: (1) the required amount of water weight. to the 100 per cent wax formulation from Step as h ated t 0 F-; (2) ammonium-hydroxide was 111, with slow stirring. A variation of this step, as shown added;(3)the proteinaceous material was added in the in Example 7, resides in the addition of the ureaform of a 30 per cent mixture in water at a temperature formaldehyde resin before homogenization; however in of 75 F.; (4) the require m n of ax n il r such instance the resulting emulsion exhibits consideramixed and heated to a temperature of 230 F. and bly higher viscosity after a periof of 12 to 14 days. added; (5) and the required amount of clay was added At the conclusion ofStep .lV. the wax emulsion prepat a temperature of 75 F. The blender was operated at aration is complete and may be poured or pumped into high speed for a period of 2 minutes between additions. a suitable container for storage.

Table l Wax Emulsions EXAMPLE NO. I 3 3 4 5 h 7 8 9 10 Basic L'F*" UF in Ani- Non Non onic formu added formuemulsiionic ionic lation lation ficr emulsiemulsifier fler MATERIAL 125/127 AMP Paraffin Wax 59.5 49.1 48.6 46.4 57.85 57.85 57.85 57.85 57.85 57.85 100" Solvent Refined Paraffinic Neutral Oil 1.8 Ammonium Hydroxide Trace (10 .60 .60 .30 .30 Soluble blood at F. 0.5 Soy Flour 1.8 1.8 l 8 Alpha Soy Protein 1 50 1.50 I 50 l 50 l 50 l 50 Sodium Salt of Pcntachlorophenol so 60 60 .60 .30 .0 Oleic Acid 200 Table 1 Continued Wax Emulsions* EXAMPLE NO. 1 2 3 4 5 6 7 8 9 l Sorbitan Monooleate 3 Ethylene Oxide Sorbitan Monooleate 30 UP Resin 2.00 Clay .6 1.8 2.09 2.09 2.09 2.09 2.09 2.09 Water 40.0 49.1 49.0 48.2 37.36 37.36 35.36 35.36 37.36 37.36 Total 100.0 100.0 100.0 100.0 100.00 100.00 100.00 100.00 100.00 100.00 Nominal solids. 71 60 50 50 50 63 63 65 65 63 63 pH Tolerance:

Acetic Acid. trace good Ammonium Hydroxide, trace good Hand Shear poor good good poor (granular) Disc Shear. grams 3.5 1.5 16 Pump Shear. grams 2.1 .5 .8 Observations Creaming No Good Shelf Stability Poor Shelf Stability poor Creaming Stability in Became Viscous 48 hours in 12 days Examples I-4 made in 200 gram batches in blender. Examples -10 made in 2000 gram batches in Manton-Gaulin Homogenizer. All Quantities are in weight percent.

"Urea-formaldehyde resin added after basic formulation cooled overnight: 100 parts wax emulsion wet weight to 3 parts UF resin wet weight added with slow stirring.

As is shown in Examples 1 and 2 ofTable l. the emulsions made on the blender exhibited creaming and poor shelf stability. The emulsions of Examples 3 and 4 exhibited good shelf stability when clay was added. However. it will be noted that all of the emulsions of Examples 1 through 4 exhibited poor hand shear.

Upon the addition of the urea-formaldehyde resin, it will be noted from Examples 6 and 7 that the shear stability of the wax emulsion was significantly improved. Hand shear. disc shear and pump shear, as in Examples 6 and 7. exhibited low wax shear-out when compared with Example 5, which comprised the basic formulation but without the presence ofthe urea-formaldehyde resin. it will be noted, as shown in Example 6, that in order to avoid an increase in viscosity with time, the urea-formaldehyde resin must be added after the basic emulsion has cooled.

The ability of the urea-formaldehyde resin to improve shear stability was quite unexpected. The use of conventional emulsifiers, as shown in Examples 8, 9 and 10. exhibited poor shear stability and poor shelf stability. The ability of the urea-formaldehyde resin to improve the shear stability was even more remarkable for the reason that many additives which are normally considered to be more compatible (such as methanol. ethanol. ethylene glycol and urea) resulted in exhibiting extremely poor shear stability.

Data were next obtained for comparing the water resistance of the novel protein wax emulsion of the present invention in particle board with that of four commercially available standard wax emulsions having different emulsifier systems, as shown in the following Table 11. Emulsion system A comprised a cationic emulsion containing 65 per cent, by weight, solids. Emulsion system B comprised an amine soap emulsion containing per cent, by weight, solids. Emulsion system C also comprised an amine soap emulsion containing per cent, by weight, solids. Emulsion system D comprised a gum-type emulsion containing 45 per cent, by weight, solids. Emulsion system E comprised the protein emulsifier of the present invention containing, by weight, 63 per cent solids. The particle boards were made at three levels of net wax solids, viz. 0.75%, 0.50% and 0.35%. In Table II are shown the comparative water resistance and thickness swell data for the protein emulsion of the aforementioned Example 6 of Table l and the aforementioned commercial emulsions A, B, C and D in particle board.

The data of Table ll represent computer data based on the sums of squares analysis at a probability level. The particle boards employed comprised single layer homogeneous Douglas fir made with 6 per cent urea-formaldehyde resin solids. The board dimensions were 0.50 inch X 12 inches X 18 inches bonded at 300 F./7 minutes and post-cured at F/3 hours with slow cooling to room temperature. The testing was conducted in accordance with US. Specification ASTM- l037-62T and European Specification DIN-52-364.

From the foregoing data of Table ll it will be noted that the protein wax emulsions of the present invention compared satisfactorily with commercial wax emulsions in particle board water resistance. It will also be noted that both water absorption and thickness swell data obtained were within specific requirements even on the 0.35% wax level.

Although the present invention has been described with preferred embodiments, it will be understood that various modifications and adaptations thereof may be resorted to without departing from the spirit and scope of the invention.

What is claimed is:

1. An emulsion suitable for use as a coating or waterproofing agent consisting essentially of, by weight, from about 25 to about 70 percent wax, from about 0.2 to about l percent of an amphoteric proteinaceous emulsifier, from about 0.5 to about 10 percent of a clay, from about b 0.5 to about percent of an ureaformaldehyde resin and water in an amount sufficient to form the emulsion.

2. An emulsion as defined in claim 1 comprising, by weight, from about 45 to about 65 per cent wax, from about 0.5 to about 3 per cent amphoteric proteinaceous emulsifier, from about 1 to about 5 per cent clay, from about 1 to about 5 per cent ureaformaldehyde resin and water in an amount sufficient to form the emulsion.

3. An emulsion as defined in claim 1 wherein said wax is selected from the group consisting of petroleum and natural waxes.

4. An emulsion as defined in claim 1 wherein said clay comprises a natural clay.

5. An emulsion as defined in claim 1 wherein said amphoteric proteinaceous emulsifier comprises an alpha-soy protein.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,869, rl DATED I March t, 1975 TNVENTOMS) I CRAIG C. CAMPBELL It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 36 or should read --of--. Column 3, line #3 LOT should read --ltOF--., Column 4, line t? "periof" should read --period--. Column 6, Table I ".30" under Column 10 should be (Continued) under Column 9.

Column 9 Claim 1 Delete "13" before 0 S.

Llne 20 Signed and Scaled this second Day of December 1975 [SEAL] A nest:

RUTH C. MASON C. MARSHALL BARN Arresting Officer Commissioner ofPatents and Trademarks UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,869,Lr1h DATED 1 March 4, 1975 VENTOR( 3 CRAIG C. CAMPBELL Itis certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 36 "or" should read --of--. Column 3, line L3 lOF" should read --l- IOF--. Column L line +7 "periof" should read --period--. Column 6, Table I ".30" under Column 10 should be (Continued) under Column 9.

Column 9 Claim 1 Delete "b" before 0 5 Llne 2O Signed and Scaled this second Day of December1975 [SEAL] Arrest:

RUTH C. MASON C. IARSIIALL DANN A nesting Officer Commission" ofPnlents and Tndenlllrks 

1. AN EMULSION SUITABLE FOR USE AS A COATING OR WATERPROOFING AGENT CONSISTING ESSENTIALLY OF, BY WEIGHT, FROM ABOUT 25 TO ABOUT 70 PERCENT WAX, FROM ABOUT 0.2 TO ABOUT 10 PERCENT OF AN AMPHPTERIC PROTEINACEOUS EMULSIFIER, FROM ABOUT 0.5 TO ABOUT 10 PERCENT OF A CLAY, FROM ABOUT B 0/5 TO ABOUT 15 PERCENT OF AN UREA-FORMALDEHYDE RESIN AND WATER IN AN AMOUNT SUFFICIENT TO FORM THE EMULSION.
 2. An emulsion as defined in claim 1 comprising, by weight, from about 45 to about 65 per cent wax, from about 0.5 to about 3 per cent amphoteric proteinaceous emulsifier, from about 1 to about 5 per cent clay, from about 1 to about 5 per cent urea-formaldehyde resin and water in an amount sufficient to form the emulsion.
 3. An emulsion as defined in claim 1 wherein said wax is selected from the group consisting of petroleum and natural waxes.
 4. An emulsion as defined in claim 1 wherein said clay comprises a natural clay.
 5. An emulsion as defined in claim 1 wherein said amphoteric proteinaceous emulsifier comprises an alpha-soy protein. 